Together with spindles, K-complexes are well known hallmarks of stage 2 sleep (S2). However, little is known about their topographical distribution in comparison to delta-waves and to K-complexes ...superimposed by spindles.
In this study, the topographical distribution of spontaneous K-complexes and delta-waves in S2 and delta-waves in stage 4 sleep (S4) in 10 healthy young adults (aged 20 to 35 years, 7 female) was investigated. K-complexes with and without spindles in S2, delta-waves with and without spindles in S2, and delta-waves in S4 distributed all over the night were visually selected. EEG power maps and statistical parametric maps were calculated.
Absolute delta power of S2 K-complexes appeared to be significantly higher than of S2 delta-waves and delta power of S4 delta-waves was higher than of S2 delta-waves. In K-complexes and delta-waves, power was found to be highest over medio-frontal regions in the delta frequency band (0.5-4.0 Hz) with a second maximum occipitally in delta-waves, no matter whether superimposed by a spindle or not.
K-complexes and delta-waves in S2 differ in topographical distribution. Even though in S2 delta-waves have less power, they have a similar topographical distribution in S2 and S4, supporting the hypothesis that delta-waves in S2 further develop towards delta-waves in slow wave sleep. The delta frequency components of K-complexes and delta-waves are unaffected by spindles.
In clinical practice, the quality of polysomnographic recordings in children and patients with neurodegenerative diseases may be affected by sensor displacement and diminished total sleep time due to ...stress during the recording. In the present study, we investigated if contactless three‐dimensional (3D) detection of periodic leg movements during sleep was comparable to polysomnography. We prospectively studied a sleep laboratory cohort from two Austrian sleep laboratories. Periodic leg movements during sleep were classified according to the standards of the World Association of Sleep Medicine and served as ground truth. Leg movements including respiratory‐related events (A1) and excluding respiratory‐related events (A2 and A3) were presented as A1, A2 and A3. Three‐dimensional movement analysis was carried out using an algorithm developed by the Austrian Institute of Technology. Fifty‐two patients (22 female, mean age 52.2 ± 15.1 years) were included. Periodic leg movement during sleep indexes were significantly higher with 3D detection compared to polysomnography (33.3 8.1–97.2 vs. 30.7 2.9–91.9: +9.1%, p = .0055/27.8 4.5–86.2 vs. 24.2 0.00–88.7: +8.2%, p = .0154/31.8 8.1–89.5 vs. 29.6 2.4–91.1: +8.9%, p = .0129). Contactless automatic 3D analysis has the potential to detect restlessness mirrored by periodic leg movements during sleep reliably and may especially be suited for children and the elderly.
Functional significance of stage 2 sleep spindle activity for declarative memory consolidation.
Randomized, within-subject, multicenter.
Weekly sleep laboratory visits, actigraphy, and sleep diary (4 ...weeks).
Twenty-four healthy subjects (12 men) aged between 20 and 30 years.
Declarative memory task or nonlearning control task before sleep.
This study measured spindle activity during stage 2 sleep following a (declarative) word-pair association task as compared to a control task. Participants performed a cued recall in the evening after learning (160 word pairs) as well as in the subsequent morning after 8 hours of undisturbed sleep with full polysomnography. Overnight change in the number of recalled words, but not absolute memory performance, correlated significantly with increased spindle activity during the experimental night (r24 = .63, P < .01). Time spent in each sleep stage could not account for this relationship.
A growing body of evidence supports the active role of sleep for information reprocessing. Whereas past research focused mainly on the distinct rapid eye movement and slow-wave sleep, these results indicate that increased sleep stage 2 spindle activity is related to an increase in recall performance and, thus, may reflect memory consolidation.
Sleep coaching by Holzinger & Klösch™ is a new, Gestalt therapy-based holistic approach to non-pharmacological treatment of non-restorative sleep. It includes psychotherapeutic aspects which enable ...participants to improve their sleep quality by developing their own coping strategies as a daily routine. Dream work and relaxation techniques are also part of the programme. The aim of this study was to measure the effectiveness of a two-day sleep coaching seminar on sleep quality, daytime sleepiness, and work and life quality in shift workers employed in an Austrian railway company (Österreichische Bundesbahnen, ÖBB). Thirty shift workers (28 male; mean age=24±45.90, age range 24–56 years) answered the same survey before and six months after the seminar (baseline and follow-up) containing items of the Pittsburgh Sleep Quality Index (PSQI) and the Epworth Sleepiness Scale (ESS), their chronotype, personality factors, and burnout risk factors. The baseline findings in this group were compared with those of non-completers (who did not take the follow-up survey) (N=154) to see if the two groups differed significantly enough to create a bias among completers (who took the follow-up survey as well). Groups differed significantly in burnout levels as well as sleep duration, but not in the distribution of critical PSQI and ESS values. The two-day sleep coaching seminar resulted in a significant improvement in total PSQI score and subjective sleep quality and in a significant reduction in diurnal fatigue, sleep latency, and daytime sleepiness. Nevertheless, more research with a larger sample and a longitudinal design is needed to establish the long-term effects of sleep coaching.
Sleep and memory studies often focus on overnight rather than long‐term memory changes, traditionally associating overnight memory change (OMC) with sleep architecture and sleep patterns such as ...spindles. In addition, (para‐)sympathetic innervation has been associated with OMC after a daytime nap using heart rate variability (HRV). In this study we investigated overnight and long‐term performance changes for procedural memory and evaluated associations with sleep architecture, spindle activity (SpA) and HRV measures (R‐R interval RRI, standard deviation of R‐R intervals SDNN, as well as spectral power for low LF and high frequencies HF). All participants (N = 20, Mage = 23.40 ± 2.78 years) were trained on a mirror‐tracing task and completed a control (normal vision) and learning (mirrored vision) condition. Performance was evaluated after training (R1), after a full‐night sleep (R2) and 7 days thereafter (R3). Overnight changes (R2‐R1) indicated significantly higher accuracy after sleep, whereas a significant long‐term (R3‐R2) improvement was only observed for tracing speed. Sleep architecture measures were not associated with OMC after correcting for multiple comparisons. However, individual SpA change from the control to the learning night indicated that only “SpA enhancers” exhibited overnight improvements for accuracy and long‐term improvements for speed. HRV analyses revealed that lower SDNN and LF power was associated with better OMC for the procedural speed measure. Altogether, this study indicates that overnight improvement for procedural memory is specific for spindle enhancers, and is associated with HRV during sleep following procedural learning.
Background
Polysomnography systems used for the diagnosis of sleep respiratory disorders are comprised of multiple sensors, including abdomen and thorax respiratory inductance plethysmography (RIP) ...belts to record respiratory effort. However, RIP belts are known to be susceptible to signal loss. To resolve this, we utilized a contactless three-dimensional (3D) time-of-flight (TOF) camera to monitor respiratory effort.
Objective
We aimed to show that respiratory effort monitoring can be achieved by 3D TOF camera recording instead of RIP belts.
Materials and methods
The use of RIP belt signals is twofold. Firstly, the signals are used to classify the apnea events into obstructive, central, and mixed. Additionally, the American Academy of Sleep Medicine (AASM) Scoring Manual recommends the scoring of apneas and hypopneas using RIPSum (the sum of the abdomen and thorax RIP signals) when the airflow sensors are unavailable. We therefore used the 3D effort signal to classify apneas and compared it to the RIP signal classification. Reduced effort events from RIP and 3D effort signals were compared to the apnea and hypopnea events. Furthermore, the changes in effort during the events were compared between the two effort signals.
Results
Classification by 3D effort signal performed well, with 80% accuracy. It worked best for central apneas, with an accuracy of 99%. There was a high correlation of
r
= 0.88 (r ≠ 0,
p
= 0.0001) between the 3D effort signal events and RIPSum events. There was also a significant correlation of 0.62 (r ≠ 0,
p
= 0.0001) between 3D effort signal and RIPSum in the decrease of effort during apnea and hypopnea events.
Conclusion
We conclude that respiratory effort derived from a 3D TOF camera can be used as an alternative to RIP belts for scoring of apneas and hypopneas and classification of apneas.
BackgroundPolysomnography systems used for the diagnosis of sleep respiratory disorders are comprised of multiple sensors, including abdomen and thorax respiratory inductance plethysmography (RIP) ...belts to record respiratory effort. However, RIP belts are known to be susceptible to signal loss. To resolve this, we utilized a contactless three-dimensional (3D) time-of-flight (TOF) camera to monitor respiratory effort.ObjectiveWe aimed to show that respiratory effort monitoring can be achieved by 3D TOF camera recording instead of RIP belts.Materials and methodsThe use of RIP belt signals is twofold. Firstly, the signals are used to classify the apnea events into obstructive, central, and mixed. Additionally, the American Academy of Sleep Medicine (AASM) Scoring Manual recommends the scoring of apneas and hypopneas using RIPSum (the sum of the abdomen and thorax RIP signals) when the airflow sensors are unavailable. We therefore used the 3D effort signal to classify apneas and compared it to the RIP signal classification. Reduced effort events from RIP and 3D effort signals were compared to the apnea and hypopnea events. Furthermore, the changes in effort during the events were compared between the two effort signals.ResultsClassification by 3D effort signal performed well, with 80% accuracy. It worked best for central apneas, with an accuracy of 99%. There was a high correlation of r = 0.88 (r ≠ 0, p = 0.0001) between the 3D effort signal events and RIPSum events. There was also a significant correlation of 0.62 (r ≠ 0, p = 0.0001) between 3D effort signal and RIPSum in the decrease of effort during apnea and hypopnea events.ConclusionWe conclude that respiratory effort derived from a 3D TOF camera can be used as an alternative to RIP belts for scoring of apneas and hypopneas and classification of apneas.
Background: The prevalence and characteristics of morning headaches (MH) in habitual snorers are not well known, with only one retrospective study reporting MH in 23.5% of snorers. The role of MH in ...bed partners of snorers has not yet been examined. Therefore, the objective of this study was to assess MH prospectively in habitual snorers and their bed partners.
Methods: We recruited habitual snorers and their bed partners via newspaper articles. The participants completed a semistructured interview, filled in questionnaires about sleep quality, daytime sleepiness, depression and anxiety and kept a 90-day headache and sleep diary.
Results: We included a total of 102 snorers and 63 bed partners. Seventy-six snorers (25 female) and 41 bed partners (31 female) completed the study, recording a total of 6690 and 3497 diary days, respectively. MH was present on at least 1 day in 57% of the snorers and in 61% of the bed partners and recorded on 7.2% and 3.6% of the diary days, respectively. Independent predictors of MH in snorers were pre-study headache frequency (p < 0.001), anxiety disorder (p < 0.001), waking up because of pain (p = 0.002) and waking up too early (p < 0.001); and independent predictors in bed partners were migraine (p = 0.02), difficulties breathing during sleep (p < 0.001), waking up because of pain (p = 0.01) and waking up too early (p < 0.001). The analysis of couples only (n = 41) revealed pre-study headache frequency (p < 0.001), waking up too early (p < 0.001) and nocturnal confusion (p < 0.001) as independent predictors of MH in snorers, and migraine (p = 0.02), difficulties breathing during sleep (p < 0.001), waking up because of pain (p = 0.01) and waking up too early (p < 0.001) as independent predictors in bed partners.
Discussion: MH shows a 90-day prevalence of around 60% in habitual snorers as well as in their bed partners. Predictors of MH are related to sleep, headache and psychiatric comorbidity.
The International Pharmaco-EEG Society (IPEG) presents guidelines summarising the requirements for the recording and computerised evaluation of pharmaco-sleep data in man. Over the past years, ...technical and data-processing methods have advanced steadily, thus enhancing data quality and expanding the palette of sleep assessment tools that can be used to investigate the activity of drugs on the central nervous system (CNS), determine the time course of effects and pharmacodynamic properties of novel therapeutics, hence enabling the study of the pharmacokinetic/pharmacodynamic relationship, and evaluate the CNS penetration or toxicity of compounds. However, despite the presence of robust guidelines on the scoring of polysomnography -recordings, a review of the literature reveals inconsistent -aspects in the operating procedures from one study to another. While this fact does not invalidate results, the lack of standardisation constitutes a regrettable shortcoming, especially in the context of drug development programmes. The present guidelines are intended to assist investigators, who are using pharmaco-sleep measures in clinical research, in an effort to provide clear and concise recommendations and thereby to standardise methodology and facilitate comparability of data across laboratories.
Autonomic dysfunction in PD during sleep Schaller, Stefan; Anderer, Peter; Dorffner, Georg ...
Movement disorders,
March 2012, Letnik:
27, Številka:
3
Journal Article
PDF
